28420247 has 2 divisors, whose sum is σ = 28420248. Its totient is φ = 28420246.

The previous prime is 28420237. The next prime is 28420253. The reversal of 28420247 is 74202482.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28420247 - 2¹² = 28416151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28420237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14210123 + 14210124.

It is an arithmetic number, because the mean of its divisors is an integer number (14210124).

Almost surely, 2^28420247 is an apocalyptic number.

28420247 is a deficient number, since it is larger than the sum of its proper divisors (1).

28420247 is an equidigital number, since it uses as much as digits as its factorization.

28420247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7168, while the sum is 29.

The square root of 28420247 is about 5331.0643402608. The cubic root of 28420247 is about 305.1705469179.

The spelling of 28420247 in words is "twenty-eight million, four hundred twenty thousand, two hundred forty-seven".